Crowti (also known as Cryptowall) and Tescrypt (also known as Teslacrypt) are two ransomware families that have infected over half a million PCs running Microsoft security software in the first half of 2015. Since the start of 2015, we've observed Crowti to be the most prevalent ransomware overall, accounting for 30% of all ransomware families, as shown in Figure 1.

Figure 1. Top 10 Ransomware (January to June 2015)

Figure 2. Top 10 Ransomware (May 2015)

Figure 3. Top 10 Ransomware (June 2015)

Notice in particular that Tescrypt sits within the six families that each had less than a 5% share of the total. This is because Tescrypt is relatively new â€“ while we've seen big detection numbers between April and June, it still hasn't been enough to wipe out Crowti and Krypterade.

While Tescrypt has only been prevalent since April 2015, we've seen its infection rate spike dramatically during that time. Figure 2 shows the share it had during May, where it increased by over 600%.

Download and update

Submit a file

Recently published

Please note: While your feedback is very important to us, we do
not respond to individual submissions through this channel. Feedback, requests,
or questions submitted through this form are monitored, however responses are not
generated. If you require support, please visit the
Safety & Security Center.